Multi-subject device access authorization

ABSTRACT

An example operation may include one or more one or more of receiving two or more authorization decisions from two or more authorization entities into a blockchain system, recording the two or more authorization decisions into one or more blocks of a blockchain of the blockchain system, determining, by the blockchain system, whether the two or more authorization decisions satisfy a policy to authorize access to at least one of a device or identifiable content on the device, and when the two or more authorization decisions satisfy the policy, authorizing access to a public key that can be used to gain access to the device.

TECHNICAL FIELD

This application generally relates to a database storage system, andmore particularly, to multi-subject device access authorization.

BACKGROUND

A centralized database stores and maintains data in one single database(e.g., database server) at one location. This location is often acentral computer, for example, a desktop central processing unit (CPU),a server CPU, or a mainframe computer. Information stored on acentralized database is typically accessible from multiple differentpoints. Multiple users or client workstations can work simultaneously onthe centralized database, for example, based on a client/serverconfiguration. A centralized database is easy to manage, maintain, andcontrol, especially for purposes of security because of its singlelocation. Within a centralized database, data redundancy is minimized asa single storing place of all data also implies that a given set of dataonly has one primary record.

However, a centralized database suffers from significant drawbacks. Forexample, a centralized database has a single point of failure. Inparticular, if there are no fault-tolerance considerations and a failureoccurs (for example a hardware, firmware, and/or a software failure),all data within the database is lost and work of all users isinterrupted. In addition, centralized databases are highly dependent onnetwork connectivity. As a result, the slower the connection, the amountof time needed for each database access is increased. Another drawbackis the occurrence of bottlenecks when a centralized database experienceshigh traffic due to a single location. Furthermore, a centralizeddatabase provides limited access to data because only one copy of thedata is maintained by the database. As a result, multiple devices cannotaccess the same piece of data at the same time without creatingsignificant problems or risk overwriting stored data. Furthermore,because a database storage system has minimal to no data redundancy,data that is unexpectedly lost is very difficult to retrieve other thanthrough manual operation from back-up storage.

Recently, the issue of unlocking a secure mobile device, for criminalinvestigation, was the subject of public debate. Device manufacturershave argued that giving law enforcement agencies the power to unlock anydevice, for criminal investigation, implies weakening the security levelof their product hence making all devices more vulnerable to attacks byhackers. Manufacturers argued that weakening the security of all devicesis not desired as it would also give more power to attackers.Furthermore, giving the authority to unlock all devices to a singleentity is not acceptable from a privacy perspective.

As such, what is needed is a solution to overcome these significantdrawbacks.

SUMMARY

One example embodiment provides a system that includes two or moreauthorization entities and a blockchain system configured to perform oneor more of receive two or more authorization decisions from the two ormore authorization entities, record the two or more authorizationdecisions into one or more blocks of a blockchain of the blockchainsystem, determine, by the blockchain system, whether the two or moreauthorization decisions satisfy a policy to authorize access to at leastone of a device or identifiable content on the device, and authorizeaccess to a public key that can be used to gain access to the devicewhen the two or more authorization decisions satisfy the policy.

Another example embodiment provides a method that includes one or moreof receiving two or more authorization decisions from two or moreauthorization entities into a blockchain system, recording the two ormore authorization decisions into one or more blocks of a blockchain ofthe blockchain system, determining, by the blockchain system, whetherthe two or more authorization decisions satisfy a policy to authorizeaccess to at least one of a device or identifiable content on thedevice, and when the two or more authorization decisions satisfy thepolicy, authorizing access to a public key that can be used to gainaccess to the device.

A further example embodiment provides a non-transitory computer readablemedium comprising instructions, that when read by a processor, cause theprocessor to perform one or more of receiving two or more authorizationdecisions from two or more authorization entities into a blockchainsystem, recording the two or more authorization decisions into one ormore blocks of a blockchain of the blockchain system, determining, bythe blockchain system, whether the two or more authorization decisionssatisfy a policy to authorize access to at least one of a device oridentifiable content on the device, and when the two or moreauthorization decisions satisfy the policy, authorizing access to apublic key that can be used to gain access to the device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a network entity diagram of a system including ablockchain system, according to example embodiments.

FIG. 1B illustrates interactions between entities of the system,according to example embodiments.

FIG. 2A illustrates an example peer node configuration, according toexample embodiments.

FIG. 2B illustrates a further peer node configuration, according toexample embodiments.

FIG. 3 illustrates a permissioned network, according to exampleembodiments.

FIG. 4 illustrates a system messaging diagram, according to exampleembodiments.

FIG. 5A illustrates a flow diagram, according to example embodiments.

FIG. 5B illustrates a further flow diagram, according to exampleembodiments.

FIG. 6A illustrates an example system configured to perform one or moreoperations described herein, according to example embodiments.

FIG. 6B illustrates a further example system configured to perform oneor more operations described herein, according to example embodiments.

FIG. 6C illustrates a smart contract configuration among contractingparties and a mediating server configured to enforce the smart contractterms on the blockchain according to example embodiments.

FIG. 6D illustrates an additional example system, according to exampleembodiments.

FIG. 7A illustrates a flow of new data being added to a database,according to example embodiments.

FIG. 7B illustrates contents of a data block including the new data,according to example embodiments.

FIG. 7C illustrates a further flow of a blockchain.

FIG. 7D illustrates further contents of a data block including the newdata, according to example embodiments.

FIG. 8 illustrates an example system that supports one or more of theexample embodiments.

DETAILED DESCRIPTION

It will be readily understood that the instant components, as generallydescribed and illustrated in the figures herein, may be arranged anddesigned in a wide variety of different configurations. Thus, thefollowing detailed description of the embodiments of at least one of amethod, apparatus, non-transitory computer readable medium and system,as represented in the attached figures, is not intended to limit thescope of the application as claimed but is merely representative ofselected embodiments.

The instant features, structures, or characteristics as describedthroughout this specification may be combined in any suitable manner inone or more embodiments. For example, the usage of the phrases “exampleembodiments”, “some embodiments”, or other similar language, throughoutthis specification refers to the fact that a particular feature,structure, or characteristic described in connection with the embodimentmay be included in at least one embodiment. Thus, appearances of thephrases “example embodiments”, “in some embodiments”, “in otherembodiments”, or other similar language, throughout this specificationdo not necessarily all refer to the same group of embodiments, and thedescribed features, structures, or characteristics may be combined inany suitable manner in one or more embodiments.

In addition, while the term “message” may have been used in thedescription of embodiments, the application may be applied to many typesof network data, such as, packet, frame, datagram, etc. The term“message” also includes packet, frame, datagram, and any equivalentsthereof. Furthermore, while certain types of messages and signaling maybe depicted in exemplary embodiments they are not limited to a certaintype of message, and the application is not limited to a certain type ofsignaling.

Example embodiments provide methods, systems, components, non-transitorycomputer readable media, devices, and/or networks, which provideauthorization control for accessing information or content on a device.

A decentralized database is a distributed storage system which includesmultiple nodes that communicate with each other. A blockchain is anexample of a decentralized database which includes an append-onlyimmutable data structure resembling a distributed ledger capable ofmaintaining records between mutually untrusted parties. The untrustedparties are referred to herein as peers or peer nodes. Each peermaintains a copy of the database records and no single peer can modifythe database records without a consensus being reached among thedistributed peers. For example, the peers may execute a consensusprotocol to validate blockchain storage transactions, group the storagetransactions into blocks, and build a hash chain over the blocks. Thisprocess forms the ledger by ordering the storage transactions, as isnecessary, for consistency. In a public or permission-less blockchain,anyone can participate without a specific identity. Public blockchainsoften involve native cryptocurrency and use consensus based on variousprotocols such as Proof of Work (PoW). On the other hand, a permissionedblockchain database provides a system which can secure inter-actionsamong a group of entities which share a common goal but which do notfully trust one another, such as businesses that exchange funds, goods,information, and the like.

A blockchain operates arbitrary, programmable logic, tailored to adecentralized storage scheme and referred to as “smart contracts” or“chaincodes.” In some cases, specialized chaincodes may exist formanagement functions and parameters which are referred to as systemchaincode. Smart contracts are trusted distributed applications whichleverage tamper-proof properties of the blockchain database and anunderlying agreement between nodes which is referred to as anendorsement or endorsement policy. In general, blockchain transactionstypically must be “endorsed” before being committed to the blockchainwhile transactions which are not endorsed are disregarded. A typicalendorsement policy allows chaincode to specify endorsers for atransaction in the form of a set of peer nodes that are necessary forendorsement. When a client sends the transaction to the peers specifiedin the endorsement policy, the transaction is executed to validate thetransaction. After validation, the transactions enter an ordering phasein which a consensus protocol is used to produce an ordered sequence ofendorsed transactions grouped into blocks.

Nodes are the communication entities of the blockchain system. A “node”may perform a logical function in the sense that multiple nodes ofdifferent types can run on the same physical server. Nodes are groupedin trust domains and are associated with logical entities that controlthem in various ways. Nodes may include different types, such as aclient or submitting-client node which submits a transaction-invocationto an endorser (e.g., peer), and broadcasts transaction-proposals to anordering service (e.g., ordering node). Another type of node is a peernode which can receive client submitted transactions, commit thetransactions and maintain a state and a copy of the ledger of blockchaintransactions. Peers can also have the role of an endorser, although itis not a requirement. An ordering-service-node or orderer is a noderunning the communication service for all nodes, and which implements adelivery guarantee, such as a broadcast to each of the peer nodes in thesystem when committing transactions and modifying a world state of theblockchain, which is another name for the initial blockchain transactionwhich normally includes control and setup information.

A ledger is a sequenced, tamper-resistant record of all statetransitions of a blockchain. State transitions may result from chaincodeinvocations (i.e., transactions) submitted by participating parties(e.g., client nodes, ordering nodes, endorser nodes, peer nodes, etc.).A transaction may result in a set of asset key-value pairs beingcommitted to the ledger as one or more operands, such as creates,updates, deletes, and the like. The ledger includes a blockchain (alsoreferred to as a chain) which is used to store an immutable, sequencedrecord in blocks. The ledger also includes a state database whichmaintains a current state of the blockchain. There is typically oneledger per channel. Each peer node maintains a copy of the ledger foreach channel of which they are a member.

A chain is a transaction log which is structured as hash-linked blocks,and each block contains a sequence of N transactions where N is equal toor greater than one. The block header includes a hash of the block'stransactions, as well as a hash of the prior block's header. In thisway, all transactions on the ledger may be sequenced andcryptographically linked together. Accordingly, it is not possible totamper with the ledger data without breaking the hash links. A hash of amost recently added blockchain block represents every transaction on thechain that has come before it, making it possible to ensure that allpeer nodes are in a consistent and trusted state. The chain may bestored on a peer node file system (i.e., local, attached storage, cloud,etc.), efficiently supporting the append-only nature of the blockchainworkload.

The current state of the immutable ledger represents the latest valuesfor all keys that are included in the chain transaction log. Because thecurrent state represents the latest key values known to a channel, it issometimes referred to as a world state. Chaincode invocations executetransactions against the current state data of the ledger. To make thesechaincode interactions efficient, the latest values of the keys may bestored in a state database. The state database may be simply an indexedview into the chain's transaction log, it can therefore be regeneratedfrom the chain at any time. The state database may automatically berecovered (or generated if needed) upon peer node startup, and beforetransactions are accepted.

Some benefits of the instant solutions described and depicted hereininclude an ability to record authorizations to access information frommultiple authorities in a manner that prevents access to privateinformation by a single entity. Authorizations are recorded in theblockchain and are therefore immutable. Chaincode and/or smart contractscan be used to process authorizations and consensus systems candetermine whether access to private information should be granted, allof which can be recorded in the blockchain and later audited.

Blockchain is different from a traditional database in that blockchainis not a central storage but rather a decentralized, immutable, andsecure storage, where nodes must share in changes to records in thestorage. Some properties that are inherent in blockchain and which helpimplement the blockchain include, but are not limited to, an immutableledger, smart contracts, security, privacy, decentralization, consensus,endorsement, accessibility, and the like, which are further describedherein. According to various aspects, the privacy control is implementeddue to consensus processes which are inherent and unique to blockchain.In particular, access to a privacy key will only be granted under rulesrequiring consensus amongst multiple authorization entities. These rulesmay be embedded in chaincode and/or smart contracts so that particulardecision making is not left up to a single entity or entities but arisesout of the consensus policies of the blockchain.

Through the blockchain system described herein, a computing system canperform functionality of allowing access to private data protected by apublic/private key pair because the public key that controls access tothe private data is only released if consensus policies of theblockchain are satisfied, with all authorization data being logged inthe blockchain, making the authorization data immutable. Theimmutability of the authorization data makes the authorizing entitiesfully accountable for their authorization decisions.

As outlined above, there may be times when content stored and/orprotected on a user device is of interest to various authorities, inparticular for enhancing security, counter-terrorism, etc. Inembodiments to be described herein, the decision to unlock a certaindevice may be guarded by authorizations from a number of agencies, whichmay include appropriate judicial and law enforcement entities. Thesystem to collect and validate such authorizations also should not beunder the control of any single entity.

Multi-subject access authorization for secure or confidential content,whether it is stored on a mobile device or a storage server, posessimilar technical challenges. Hence, what is required and will bedescribed herein is a system and method for providing decentralizedauditable authorization to access secure content, regardless of wherethe content physically resides.

Described herein is a distributed secure content access authorizationsystem (SCAAS) based on block chain technology. The SCAAS implements adistributed authorization system that ensures all needed authorizationapprovals from different agencies are recorded in a non-refutable blockchain transaction that acts as a gate keeper for allowing the unlockingof a device, or a piece of uniquely identifiable secure content.

In one embodiment, a unique asymmetric key pair per device or piece ofsecure/sensitive content is generated during the phase of initializationof device or creation of sensitive content. The first key in the pair,the private key, is stored securely in the device hosting the content,during the initialization phase. This key is used specifically forencrypting the communication for retrieving the secure content.Encryption may be done either using the private key or a key negotiatedusing the private key at content access time.

The second key in the pair is escrowed. It is stored in a secure vaultidentifiable by a unique id. The id is unique for each secured piece ofcontent or device. The access to the id specific secure vault, in orderto retrieve the key to communicate, is guarded by successful completionof a set of pre-defined authorizations by a number of agencies/entities.

The authorizations are recorded in a block-chain system that implementsa secure distributed ledger. Each approval is a block in a transactionchain. When all required approvals are obtained the trigger to retrievethe escrowed key from the secure vault is generated. The triggeridentifies the vault by the unique id.

Implementation of the system may require device manufactures, contentgenerators, application providers etc. to modify code to generate theprivate/public key pair at the time of the device manufacture or at thetime of content generation and to communicate the public key of theprivate/public key pair to the vault. The device may also be coded withan interface that can be used at content access time to receive thepublic key.

The blockchain system implementation is distributed across a number ofgovernmental agencies, companies, and NGOs. It is not open to untrustedminers to participate in maintaining (mining) the authorizationtransaction chains stored in that distributed ledger.

The SCAAS implements a distributed authorization system that ensures allneeded subject authorizations from a multiplicity of agencies arerecorded in a non-refutable block chain transaction that eventuallytriggers the unlocking of a piece of secure content. The system ensuresthat the decision to unlock content, or device access, cannot be made byan individual organization. Further, the authorization transactions areauditable, permanent, and cannot be altered.

While prior art escrow systems have been proposed, such systems assumebeing under control of one administrative organization. A benefit of thepresent system is that it distributes responsibility and accountabilityfor authorizing access to secure data, in particular private personaldata, across multiple entities, thereby making the system less subjectto corruption and ensuring that sensitive or private data is onlyexposed under conditions where policy requirements are met.

FIG. 1A illustrates an entity diagram of entities that may be involvedin an authorization process in accordance with example embodiments.Referring to FIG. 1A, the network 100 includes trusted entities fromindustry 102, government 104, and NGOs 106 running a block chain basedsystem for secure content access authorization 110. Device manufactures108 may also contribute.

FIG. 1B illustrates a system diagram for controlling access to contenton a device according to example embodiments. In the system 150, aunique asymmetric key pair per device or piece of secure/sensitivecontent is generated during the phase of initialization of device orcreation of sensitive content by a device manufacture 152. The first keyin the pair, a private key, is stored securely in the device hosting thecontent, during the initialization phase. This key is used specificallyfor encrypting the communication for retrieving the secure content.Encryption may be done either using the private key or a key negotiatedusing the private key at content access time.

The second key 154 in the pair is escrowed. The escrowed key 154 isstored in a secure vault 156 and is identifiable by a unique id. The idis unique for each secured piece of content or device. In oneembodiment, the secure vault may be one or more blocks of a blockchain,though other secure data storage systems will be apparent to the personskilled in the art.

The system 150 further includes a blockchain network 160 that may beused to generate authorizations for accessing keys within the vault 156.When access to an encryption key is required, a requester 162 may submitan access request 164 to the blockchain network 160. The submission ofthe access request 164 invokes an authorization process. The accessrequest 164 may include details of the access request including reasonsfor the request, data relating to the involved parties, evidencesupporting the request, etc. In one embodiment, the authorizationprocess may be implemented in chaincode or a smart contract process.

The authorization process of the blockchain network may distribute theaccess request to the authorization entities 166, which may include theNGOs, companies, agencies, etc. as shown in FIG. 1A. The authorizationentities 166 receive the request and any data associated with therequest. Each authorization entity may undertake its own authorizationprocesses according to their own internal policies to determine whetheraccess authorization should be granted. The authorization policyimplemented by each individual authorization entity may be public, knownto other entities, or private. The specific authorization policy of anauthorization entity is not considered pertinent to the presentdisclosure.

Having implemented their own authorization policy, each authorizationentity submits an authorization decision to the blockchain system 160which receives multiple authorizations 168 from the multipleauthorization entities 166. An individual authorization decision mayinclude additional data, such as any evidence to support the decision.Such additional data may be required or at least beneficial for auditingdecisions at a later time. The authorization decisions are recorded intoone or more blocks of the blockchain in association with an accessrequest ID.

As authorizations are received, the blockchain system implements its ownauthorization policy that determines whether access to a device orcontent thereon should be granted. The authorization policy may includerules that determine whether access is granted. In one embodiment,access may be granted if all authorization entities approve access. Inone embodiment, access may be granted if a threshold number ofauthorization entities approve access. In one embodiment, access may bedependent on specific entities, or combinations of entities grantingaccess. Various combinations of these embodiments may also beimplemented. The blockchain policy processes the received authorizationsand implements the policy to approve or prevent access. The policydecision is recorded in the blockchain in association with the requestID and any supporting policy evidence or data.

If the policy determines that the requirements for authorization andrelease of the public key have been met, then authorization is recordedinto the blockchain and an authorization trigger 170 is released to thesecurity vault 156. The security vault releases the key 172 to therequestor, who may then use the key to access the device or content 174.

FIG. 2A illustrates a blockchain architecture configuration 200,according to example embodiments. Referring to FIG. 2A, the blockchainarchitecture 200 may include certain blockchain elements, for example, agroup of blockchain nodes 202. The blockchain nodes 202 may include oneor more nodes 204-210 (these four nodes are depicted by example only).These nodes participate in a number of activities, such as blockchaintransaction addition and validation process (consensus). One or more ofthe blockchain nodes 204-210 may endorse transactions based onendorsement policy and may provide an ordering service for allblockchain nodes in the architecture 200. A blockchain node may initiatea blockchain authentication and seek to write to a blockchain immutableledger stored in blockchain layer 216, a copy of which may also bestored on the underpinning physical infrastructure 214. The blockchainconfiguration may include one or more applications 224 which are linkedto application programming interfaces (APIs) 222 to access and executestored program/application code 220 (e.g., chaincode, smart contracts,etc.) which can be created according to a customized configurationsought by participants and can maintain their own state, control theirown assets, and receive external information. This can be deployed as atransaction and installed, via appending to the distributed ledger, onall blockchain nodes 204-210.

The blockchain base or platform 212 may include various layers ofblockchain data, services (e.g., cryptographic trust services, virtualexecution environment, etc.), and underpinning physical computerinfrastructure that may be used to receive and store new transactionsand provide access to auditors which are seeking to access data entries.The blockchain layer 216 may expose an interface that provides access tothe virtual execution environment necessary to process the program codeand engage the physical infrastructure 214. Cryptographic trust services218 may be used to verify transactions such as asset exchangetransactions and keep information private.

The blockchain architecture configuration of FIG. 2A may process andexecute program/application code 220 via one or more interfaces exposed,and services provided, by blockchain platform 212. The code 220 maycontrol blockchain assets. For example, the code 220 can store andtransfer data, and may be executed by nodes 204-210 in the form of asmart contract and associated chaincode with conditions or other codeelements subject to its execution. As a non-limiting example, smartcontracts may be created to execute reminders, updates, and/or othernotifications subject to the changes, updates, etc. The smart contractscan themselves be used to identify rules associated with authorizationand access requirements and usage of the ledger. For example, theinformation 226 such as authorization decisions from authorizationentities may be processed by one or more processing entities (e.g.,virtual machines) included in the blockchain layer 216. The result 228may include a decision on whether to release a public key. The physicalinfrastructure 214 may be utilized to retrieve any of the data orinformation described herein.

Within chaincode, a smart contract may be created via a high-levelapplication and programming language, and then written to a block in theblockchain. The smart contract may include executable code which isregistered, stored, and/or replicated with a blockchain (e.g.,distributed network of blockchain peers). A transaction is an executionof the smart contract code which can be performed in response toconditions associated with the smart contract being satisfied. Theexecuting of the smart contract may trigger a trusted modification(s) toa state of a digital blockchain ledger. The modification(s) to theblockchain ledger caused by the smart contract execution may beautomatically replicated throughout the distributed network ofblockchain peers through one or more consensus protocols.

The smart contract may write data to the blockchain in the format ofkey-value pairs. Furthermore, the smart contract code can read thevalues stored in a blockchain and use them in application operations.The smart contract code can write the output of various logic operationsinto the blockchain. The code may be used to create a temporary datastructure in a virtual machine or other computing platform. Data writtento the blockchain can be public and/or can be encrypted and maintainedas private. The temporary data that is used/generated by the smartcontract is held in memory by the supplied execution environment, thendeleted once the data needed for the blockchain is identified.

A chaincode may include the code interpretation of a smart contract,with additional features. As described herein, the chaincode may beprogram code deployed on a computing network, where it is executed andvalidated by chain validators together during a consensus process. Thechaincode receives a hash and retrieves from the blockchain a hashassociated with the data template created by use of a previously storedfeature extractor. If the hashes of the hash identifier and the hashcreated from the stored identifier template data match, then thechaincode sends an authorization key to the requested service. Thechaincode may write to the blockchain data associated with thecryptographic details. In FIG. 2A, an authorization decision generatedby an authorization entity and is recorded into the blockchain. Onefunction may be to apply a policy to the authorizations from theauthorization entities to determine if a public key protecting a deviceor content should be released, which may be provided by one or more ofthe nodes 204-210.

FIG. 2B illustrates an example of a transactional flow 250 between nodesof the blockchain in accordance with an example embodiment. Referring toFIG. 2B, the transaction flow may include a transaction proposal 291sent by an application client node 260 to an endorsing peer node 281.The endorsing peer 281 may verify the client signature and execute achaincode function to initiate the transaction. The output may includethe chaincode results, a set of key/value versions that were read in thechaincode (read set), and the set of keys/values that were written inchaincode (write set). The proposal response 292 is sent back to theclient 260 along with an endorsement signature, if approved. The client260 assembles the endorsements into a transaction payload 293 andbroadcasts it to an ordering service node 284. The ordering service node284 then delivers ordered transactions as blocks to all peers 281-283 ona channel. Before committal to the blockchain, each peer 281-283 mayvalidate the transaction. For example, the peers may check theendorsement policy to ensure that the correct allotment of the specifiedpeers have signed the results and authenticated the signatures againstthe transaction payload 293.

Referring again to FIG. 2B, the client node 260 initiates thetransaction 291 by constructing and sending a request to the peer node281, which is an endorser. The client 260 may include an applicationleveraging a supported software development kit (SDK), such as NODE,JAVA, PYTHON, and the like, which utilizes an available API to generatea transaction proposal. The proposal is a request to invoke a chaincodefunction so that data can be read and/or written to the ledger (i.e.,write new key value pairs for the assets). The SDK may serve as a shimto package the transaction proposal into a properly architected format(e.g., protocol buffer over a remote procedure call (RPC)) and take theclient's cryptographic credentials to produce a unique signature for thetransaction proposal.

In response, the endorsing peer node 281 may verify (a) that thetransaction proposal is well formed, (b) the transaction has not beensubmitted already in the past (replay-attack protection), (c) thesignature is valid, and (d) that the submitter (client 260, in theexample) is properly authorized to perform the proposed operation onthat channel. The endorsing peer node 281 may take the transactionproposal inputs as arguments to the invoked chaincode function. Thechaincode is then executed against a current state database to producetransaction results including a response value, read set, and write set.However, no updates are made to the ledger at this point. In 292, theset of values, along with the endorsing peer node's 281 signature ispassed back as a proposal response 292 to the SDK of the client 260which parses the payload for the application to consume.

In response, the application of the client 260 inspects/verifies theendorsing peers signatures and compares the proposal responses todetermine if the proposal response is the same. If the chaincode onlyqueried the ledger, the application would inspect the query response andwould typically not submit the transaction to the ordering node service284. If the client application intends to submit the transaction to theordering node service 284 to update the ledger, the applicationdetermines if the specified endorsement policy has been fulfilled beforesubmitting (i.e., did all peer nodes necessary for the transactionendorse the transaction). Here, the client may include only one ofmultiple parties to the transaction. In this case, each client may havetheir own endorsing node, and each endorsing node will need to endorsethe transaction. The architecture is such that even if an applicationselects not to inspect responses or otherwise forwards an unendorsedtransaction, the endorsement policy will still be enforced by peers andupheld at the commit validation phase.

After successful inspection, in step 293 the client 260 assemblesendorsements into a transaction and broadcasts the transaction proposaland response within a transaction message to the ordering node 284. Thetransaction may contain the read/write sets, the endorsing peerssignatures and a channel ID. The ordering node 284 does not need toinspect the entire content of a transaction in order to perform itsoperation, instead the ordering node 284 may simply receive transactionsfrom all channels in the network, order them chronologically by channel,and create blocks of transactions per channel.

The blocks of the transaction are delivered from the ordering node 284to all peer nodes 281-283 on the channel. The transactions 294 withinthe block are validated to ensure any endorsement policy is fulfilledand to ensure that there have been no changes to ledger state for readset variables since the read set was generated by the transactionexecution. Transactions in the block are tagged as being valid orinvalid. Furthermore, in step 295 each peer node 281-283 appends theblock to the channel's chain, and for each valid transaction the writesets are committed to current state database. An event is emitted, tonotify the client application that the transaction (invocation) has beenimmutably appended to the chain, as well as to notify whether thetransaction was validated or invalidated.

FIG. 3 illustrates an example of a permissioned blockchain network 300,which features a distributed, decentralized peer-to-peer architecture,and a certificate authority 318 managing user roles and permissions. Inthis example, the blockchain user 302 may submit a transaction to thepermissioned blockchain network 310. In this example, the transactioncan be a deploy, invoke, or query, and may be issued through aclient-side application leveraging an SDK, directly through a REST API,or the like. Trusted business networks may provide access to regulatorsystems 314, such as auditors (the Securities and Exchange Commission ina U.S. equities market, for example). Meanwhile, a blockchain networkoperator system of nodes 308 manage member permissions, such asenrolling the regulator system 310 as an “auditor” and the blockchainuser 302 as a “client”. An auditor could be restricted only to queryingthe ledger whereas a client could be authorized to deploy, invoke, andquery certain types of chaincode.

A blockchain developer system 316 writes chaincode and client-sideapplications. The blockchain developer system 316 can deploy chaincodedirectly to the network through a REST interface. To include credentialsfrom a traditional data source 330 in chaincode, the developer system316 could use an out-of-band connection to access the data. In thisexample, the blockchain user 302 connects to the blockchain networkprocessor 332 through a peer node 312. Before proceeding with anytransactions, the peer node 312 retrieves the user's enrollment andtransaction certificates from the certificate authority 318. In somecases, blockchain users must possess these digital certificates in orderto transact on the permissioned blockchain network 310. Meanwhile, auser attempting to drive chaincode may be required to verify theircredentials on the traditional data source 330. To confirm the user'sauthorization, chaincode can use an out-of-band connection to this datathrough a traditional processing platform 320.

FIG. 4 illustrates a system messaging diagram for authorizing a releaseof a public key to access a device, according to example embodiments.Referring to FIG. 4, the system diagram 400 includes a requestor 410 andblockchain network 412 including authorization nodes, of which nodes414, 416 are examples. Initially, the requestor 410 sends an accessrequest 420 to the blockchain network 412 for an access key for a deviceor piece of content. The request may be received by any node of thenetwork 412 programmed to receive access requests. In variousembodiments, the receiving node may be a client node, a peer node or anordering node. The blockchain network 412 may distribute the accessrequest to the authorization nodes 414, 416 via authorization requests422, 424. In one embodiment, the distribution may be the responsibilityof an ordering node of the blockchain network 412. The blockchainnetwork 412 receives authorization decisions 426, 428 from theauthorization nodes 414, 416 and records the authorization decisionsinto a blockchain of the network 412. The blockchain network 412determines if the authorizations satisfy a policy requirement forreleasing an access key. If so, the blockchain network 412 sends a keyrequest 430 to a vault 418 which returns the key 432. The blockchainnetwork 412 forwards the key to the requestor 434.

Variations of this message flow may be contemplated. For example, theblockchain network 412 may provide an approval to the requestor 410 toretrieve the key from the vault 418 itself.

FIG. 5A illustrates a flow diagram 500 of an example method ofauthorizing access to a device, according to example embodiments.Referring to FIG. 5A, the method 500 may include receiving a pluralityof authorization decisions from a plurality of entities into ablockchain system 510. The authorization decisions relating to a requestfor access to a device or secure content. The received authorizationdecisions may include approvals or denials for access to the device orsecure content. The authorization decisions may be recorded into one ormore blocks of a blockchain 512. Determining, by the blockchain system,whether the plurality of authorizations meet a policy requirement torelease a public key to the device 514. When the plurality ofauthorizations meet the policy requirement, releasing the public key516.

FIG. 5B illustrates a flow diagram 550 of an example method of securingaccess to a device using a blockchain, according to example embodiments.At step 552, a private/public key pair is generated for the device. Theprivate key is stored on the device (step 554) and the public key isstored in a secure storage (step 556). A blockchain policy may beassociated with the public key (step 558). The blockchain policy mayinclude rules that determine how authorization to release the key willbe granted. The blockchain policy may be stored in a blockchain system(step 560). In one embodiment, the method 550 may include initiating ablockchain when the device/content is created and the public key may bestored as a first or early block in the blockchain. Requests to accessthe device/content may be added as additional blocks of that blockchain.

The blockchain may be used to store various data items of theauthorization process. These data items may include, without limitation:

-   -   Authorization action including authorizing agency ID and secure        device/Content unique ID.    -   Key access request by requesting agency including agency ID and        device/content ID    -   Key access release action including device/content ID, agency        ID, and optionally IDs of authorizing agencies.

In addition, different embodiments may store additional data items suchas:

-   -   The Key to access the device/content may be stored in a block by        the manufacturer/creator in an initiation step, instead of using        an external vault.    -   The retrieved secure content.

Typically the data items will be stored in the data section of a block.However other implementation specific choices may be made.

In an embodiment, the authorization transaction is complete and triggersthe unlocking of the security vault when a certain number of uniqueauthorizations is received from a set of identified authorizingagencies.

In an another embodiment, the policy for completion of an authorizationtransaction and triggering access to the key, specifies a pattern ofrequired authorizations to be satisfied. The pattern may be defined as aBoolean expression. For example the pattern may specify thatauthorizations are required from both agency A and B, in addition toeither agency C or D. Simply stated as a Boolean expression that examplewould be: A AND B AND (C OR D).

In another embodiment the security vault is implemented as part of thefirst block of the authorization transaction chain. The first block inthe chain is created by the creator/manufacturer and includes the keystored in an encrypted way. The Requestor creates the second block inthe authorization transaction chain, at a later time. The key insertedin the first block is decrypted only by the SCAAS system upon successfulcompletion of the authorization transaction chain according to theauthorization policy enforced.

In another embodiment, the SCAAS system does not complete its flow byreleasing the key to the Requestor, but it uses the key to retrieve thesecure content, by itself, and returns the content to the Requestor,after recording it as a final block in the same auditable non-refutableauthorization transaction chain.

In another embodiment, the step of securing the escrowed key involvesencrypting that key in multiple steps, whereby each step uses the publickey of a participating agency, in order. Releasing the escrowed keyinvolves the opposite decryption steps, where each step is executed bythe participating agency in order using its private key.

Authorizations may have an expiry, policy may specify that the set ofauthorizations have to be received within a timeframe.

It may be preferable that the different authorization entities implementdisparate authorization policies to ensure that a comprehensive range offactors are considered prior to granting access to a device/content key.

FIG. 6A illustrates an example system 600 that includes a physicalinfrastructure 610 configured to perform various operations according toexample embodiments. Referring to FIG. 6A, the physical infrastructure610 includes a module 612 and a module 614. The module 614 includes ablockchain 620 and a smart contract 630 (which may reside on theblockchain 620), that may execute any of the operational steps 608 (inmodule 612) included in any of the example embodiments. Thesteps/operations 608 may include one or more of the embodimentsdescribed or depicted and may represent output or written informationthat is written or read from one or more smart contracts 630 and/orblockchains 620. The physical infrastructure 610, the module 612, andthe module 614 may include one or more computers, servers, processors,memories, and/or wireless communication devices. Further, the module 612and the module 614 may be a same module.

FIG. 6B illustrates an example system 640 configured to perform variousoperations according to example embodiments. Referring to FIG. 6B, thesystem 640 includes a module 612 and a module 614. The module 614includes a blockchain 620 and a smart contract 630 (which may reside onthe blockchain 620), that may execute any of the operational steps 608(in module 612) included in any of the example embodiments. Thesteps/operations 608 may include one or more of the embodimentsdescribed or depicted and may represent output or written informationthat is written or read from one or more smart contracts 630 and/orblockchains 620. The physical infrastructure 610, the module 612, andthe module 614 may include one or more computers, servers, processors,memories, and/or wireless communication devices. Further, the module 612and the module 614 may be a same module.

FIG. 6C illustrates an example smart contract configuration amongcontracting parties and a mediating server configured to enforce thesmart contract terms on the blockchain according to example embodiments.Referring to FIG. 6C, the configuration 650 may represent acommunication session, an asset transfer session or a process orprocedure that is driven by a smart contract 630 which explicitlyidentifies one or more user devices 652 and/or 656. The execution,operations and results of the smart contract execution may be managed bya server 654. Content of the smart contract 630 may require digitalsignatures by one or more of the entities 652 and 656 which are partiesto the smart contract transaction. The results of the smart contractexecution may be written to a blockchain 620 as a blockchaintransaction. The smart contract 630 resides on the blockchain 620 whichmay reside on one or more computers, servers, processors, memories,and/or wireless communication devices.

FIG. 6D illustrates a system 660 including a blockchain, according toexample embodiments. Referring to the example of FIG. 6D, an applicationprogramming interface (API) gateway 662 provides a common interface foraccessing blockchain logic (e.g., smart contract 630 or other chaincode)and data (e.g., distributed ledger, etc.). In this example, the APIgateway 662 is a common interface for performing transactions (invoke,queries, etc.) on the blockchain by connecting one or more entities 652and 656 to a blockchain peer (i.e., server 654). Here, the server 654 isa blockchain network peer component that holds a copy of the world stateand a distributed ledger allowing clients 652 and 656 to query data onthe world state as well as submit transactions into the blockchainnetwork where, depending on the smart contract 630 and endorsementpolicy, endorsing peers will run the smart contracts 630.

The above embodiments may be implemented in hardware, in a computerprogram executed by a processor, in firmware, or in a combination of theabove. A computer program may be embodied on a computer readable medium,such as a storage medium. For example, a computer program may reside inrandom access memory (“RAM”), flash memory, read-only memory (“ROM”),erasable programmable read-only memory (“EPROM”), electrically erasableprogrammable read-only memory (“EEPROM”), registers, hard disk, aremovable disk, a compact disk read-only memory (“CD-ROM”), or any otherform of storage medium known in the art.

An exemplary storage medium may be coupled to the processor such thatthe processor may read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anapplication specific integrated circuit (“ASIC”). In the alternative,the processor and the storage medium may reside as discrete components.

FIG. 7A illustrates a process 700 of a new block being added to adistributed ledger 720, according to example embodiments, and FIG. 7Billustrates contents of a new data block structure 730 for blockchain,according to example embodiments. Referring to FIG. 7A, clients (notshown) may submit transactions to blockchain nodes 711, 712, and/or 713.Clients may be instructions received from any source to enact activityon the blockchain 720. As an example, clients may be applications thatact on behalf of a requester, such as a device, person or entity topropose transactions for the blockchain. The plurality of blockchainpeers (e.g., blockchain nodes 711, 712, and 713) may maintain a state ofthe blockchain network and a copy of the distributed ledger 720.Different types of blockchain nodes/peers may be present in theblockchain network including endorsing peers which simulate and endorsetransactions proposed by clients and committing peers which verifyendorsements, validate transactions, and commit transactions to thedistributed ledger 720. In this example, the blockchain nodes 711, 712,and 713 may perform the role of endorser node, committer node, or both.

The distributed ledger 720 includes a blockchain which stores immutable,sequenced records in blocks, and a state database 734 (current worldstate) maintaining a current state of the blockchain 722. Onedistributed ledger 720 may exist per channel and each peer maintains itsown copy of the distributed ledger 720 for each channel of which theyare a member. The blockchain 722 is a transaction log, structured ashash-linked blocks where each block contains a sequence of Ntransactions. Blocks may include various components such as shown inFIG. 7B. The linking of the blocks (shown by arrows in FIG. 7A) may begenerated by adding a hash of a prior block's header within a blockheader of a current block. In this way, all transactions on theblockchain 722 are sequenced and cryptographically linked togetherpreventing tampering with blockchain data without breaking the hashlinks. Furthermore, because of the links, the latest block in theblockchain 722 represents every transaction that has come before it. Theblockchain 722 may be stored on a peer file system (local or attachedstorage), which supports an append-only blockchain workload.

The current state of the blockchain 722 and the distributed ledger 722may be stored in the state database 734. Here, the current state datarepresents the latest values for all keys ever included in the chaintransaction log of the blockchain 722. Chaincode invocations executetransactions against the current state in the state database 734. Tomake these chaincode interactions extremely efficient, the latest valuesof all keys are stored in the state database 734. The state database 734may include an indexed view into the transaction log of the blockchain722, it can therefore be regenerated from the chain at any time. Thestate database 734 may automatically get recovered (or generated ifneeded) upon peer startup, before transactions are accepted.

Endorsing nodes receive transactions from clients and endorse thetransaction based on simulated results. Endorsing nodes hold smartcontracts which simulate the transaction proposals. When an endorsingnode endorses a transaction, the endorsing nodes creates a transactionendorsement which is a signed response from the endorsing node to theclient application indicating the endorsement of the simulatedtransaction. The method of endorsing a transaction depends on anendorsement policy which may be specified within chaincode. An exampleof an endorsement policy is “the majority of endorsing peers mustendorse the transaction”. Different channels may have differentendorsement policies. Endorsed transactions are forward by the clientapplication to ordering service 710.

The ordering service 710 accepts endorsed transactions, orders them intoa block, and delivers the blocks to the committing peers. For example,the ordering service 710 may initiate a new block when a threshold oftransactions has been reached, a timer times out, or another condition.In the example of FIG. 7A, blockchain node 712 is a committing peer thathas received a new data new data block 730 for storage on blockchain720. The first block in the blockchain may be referred to as a genesisblock which includes information about the blockchain, its members, thedata stored therein, etc.

The ordering service 710 may be made up of a cluster of orderers. Theordering service 710 does not process transactions, smart contracts, ormaintain the shared ledger. Rather, the ordering service 710 may acceptthe endorsed transactions and specifies the order in which thosetransactions are committed to the distributed ledger 720. Thearchitecture of the blockchain network may be designed such that thespecific implementation of ‘ordering’ (e.g., Solo, Kafka, BFT, etc.)becomes a pluggable component.

Transactions are written to the distributed ledger 720 in a consistentorder. The order of transactions is established to ensure that theupdates to the state database 734 are valid when they are committed tothe network. Unlike a cryptocurrency blockchain system (e.g., Bitcoin,etc.) where ordering occurs through the solving of a cryptographicpuzzle, or mining, in this example the parties of the distributed ledger720 may choose the ordering mechanism that best suits that network.

When the ordering service 710 initializes a new data block 730, the newdata block 730 may be broadcast to committing peers (e.g., blockchainnodes 711, 712, and 713). In response, each committing peer validatesthe transaction within the new data block 730 by checking to make surethat the read set and the write set still match the current world statein the state database 734. Specifically, the committing peer candetermine whether the read data that existed when the endorserssimulated the transaction is identical to the current world state in thestate database 734. When the committing peer validates the transaction,the transaction is written to the blockchain 722 on the distributedledger 720, and the state database 734 is updated with the write datafrom the read-write set. If a transaction fails, that is, if thecommitting peer finds that the read-write set does not match the currentworld state in the state database 734, the transaction ordered into ablock will still be included in that block, but it will be marked asinvalid, and the state database 734 will not be updated.

Referring to FIG. 7B, a new data block 730 (also referred to as a datablock) that is stored on the blockchain 722 of the distributed ledger720 may include multiple data segments such as a block header 740, blockdata 750, and block metadata 760. It should be appreciated that thevarious depicted blocks and their contents, such as new data block 730and its contents. shown in FIG. 7B are merely examples and are not meantto limit the scope of the example embodiments. The new data block 730may store transactional information of N transaction(s) (e.g., 1, 10,100, 500, 1000, 2000, 3000, etc.) within the block data 750. The newdata block 730 may also include a link to a previous block (e.g., on theblockchain 722 in FIG. 7A) within the block header 740. In particular,the block header 740 may include a hash of a previous block's header.The block header 740 may also include a unique block number, a hash ofthe block data 750 of the new data block 730, and the like. The blocknumber of the new data block 730 may be unique and assigned in variousorders, such as an incremental/sequential order starting from zero.

The block data 750 may store transactional information of eachtransaction that is recorded within the new data block 730. For example,the transaction data may include one or more of a type of thetransaction, a version, a timestamp, a channel ID of the distributedledger 720, a transaction ID, an epoch, a payload visibility, achaincode path (deploy tx), a chaincode name, a chaincode version, input(chaincode and functions), a client (creator) identify such as a publickey and certificate, a signature of the client, identities of endorsers,endorser signatures, a proposal hash, chaincode events, response status,namespace, a read set (list of key and version read by the transaction,etc.), a write set (list of key and value, etc.), a start key, an endkey, a list of keys, a Merkel tree query summary, and the like. Thetransaction data may be stored for each of the N transactions.

In some embodiments, the block data 750 may also store new data 762which adds additional information to the hash-linked chain of blocks inthe blockchain 722. The additional information includes one or more ofthe steps, features, processes and/or actions described or depictedherein. Accordingly, the new data 762 can be stored in an immutable logof blocks on the distributed ledger 720. Some of the benefits of storingsuch new data 762 are reflected in the various embodiments disclosed anddepicted herein.

The block metadata 760 may store multiple fields of metadata (e.g., as abyte array, etc.). Metadata fields may include signature on blockcreation, a reference to a last configuration block, a transactionfilter identifying valid and invalid transactions within the block, lastoffset persisted of an ordering service that ordered the block, and thelike. The signature, the last configuration block, and the orderermetadata may be added by the ordering service 710. Meanwhile, acommitter of the block (such as blockchain node 712) may addvalidity/invalidity information based on an endorsement policy,verification of read/write sets, and the like. The transaction filtermay include a byte array of a size equal to the number of transactionsin the block data 750 and a validation code identifying whether atransaction was valid/invalid.

FIG. 7C illustrates an embodiment of a blockchain 770 for digitalcontent which may be formed, managed, and tracked in accordance with theembodiments described herein. The digital content may include one ormore files and associated information. The files may include media,images, video, audio, text, links, graphics, animations, web pages,documents, or other forms of digital content. The immutable, append-onlyaspects of the blockchain serve as a safeguard to protect the integrity,validity, and authenticity of the digital content, making it suitableuse in legal proceedings where admissibility rules apply or othersettings where evidence is taken in to consideration or where thepresentation and use of digital information is otherwise of interest. Inthis case, the digital content may be referred to as digital evidence.

The blockchain may be formed in various ways. In one embodiment, thedigital content may be included in and accessed from the blockchainitself. For example, each block of the blockchain may store a hash valueof reference information (e.g., header, value, etc.) along theassociated digital content. The hash value and associated digitalcontent may then be encrypted together. Thus, the digital content ofeach block may be accessed by decrypting each block in the blockchain,and the hash value of each block may be used as a basis to reference aprevious block. This may be illustrated as follows:

Block 1 Block 2 Block N Hash Value 1 Hash Value 2 Hash Value N DigitalContent 1 Digital Content 2 Digital Content N

In one embodiment, the digital content may be not included in theblockchain. For example, the blockchain may store the encrypted hashesof the content of each block without any of the digital content. Thedigital content may be stored in another storage area or memory addressin association with the hash value of the original file. The otherstorage area may be the same storage device used to store the blockchainor may be a different storage area or even a separate relationaldatabase. The digital content of each block may be referenced oraccessed by obtaining or querying the hash value of a block of interestand then looking up that has value in the storage area, which is storedin correspondence with the actual digital content. This operation may beperformed, for example, a database gatekeeper. This may be illustratedas follows:

Blockchain Storage Area Block 1 Hash Value Block 1 Hash Value . . .Content . . . . . . Block N Hash Value Block N Hash Value . . . Content

In the example embodiment of FIG. 7C, the blockchain 770 includes anumber of blocks 778 ₁, 778 ₂, . . . 778 _(N) cryptographically linkedin an ordered sequence, where N≥1. The encryption used to link theblocks 778 ₁, 778 ₂, . . . 778 _(N) may be any of a number of keyed orun-keyed Hash functions. In one embodiment, the blocks 778 ₁, 778 ₂, . .. 778 _(N) are subject to a hash function which produces n-bitalphanumeric outputs (where n is 256 or another number) from inputs thatare based on information in the blocks. Examples of such a hash functioninclude, but are not limited to, a SHA-type (SHA stands for Secured HashAlgorithm) algorithm, Merkle-Damgard algorithm, HAIFA algorithm,Merkle-tree algorithm, nonce-based algorithm, and anon-collision-resistant PRF algorithm. In another embodiment, the blocks778 ₁, 778 ₂, . . . , 778 _(N) may be cryptographically linked by afunction that is different from a hash function. For purposes ofillustration, the following description is made with reference to a hashfunction, e.g., SHA-2.

Each of the blocks 778 ₁, 778 ₂, . . . , 778 _(N) in the blockchainincludes a header, a version of the file, and a value. The header andthe value are different for each block as a result of hashing in theblockchain. In one embodiment, the value may be included in the header.As described in greater detail below, the version of the file may be theoriginal file or a different version of the original file.

The first block 778 ₁ in the blockchain is referred to as the genesisblock and includes the header 772 ₁, original file 774 ₁, and an initialvalue 776 ₁. The hashing scheme used for the genesis block, and indeedin all subsequent blocks, may vary. For example, all the information inthe first block 778 ₁ may be hashed together and at one time, or each ora portion of the information in the first block 778 ₁ may be separatelyhashed and then a hash of the separately hashed portions may beperformed.

The header 772 ₁ may include one or more initial parameters, which, forexample, may include a version number, timestamp, nonce, rootinformation, difficulty level, consensus protocol, duration, mediaformat, source, descriptive keywords, and/or other informationassociated with original file 774 ₁ and/or the blockchain. The header772 ₁ may be generated automatically (e.g., by blockchain networkmanaging software) or manually by a blockchain participant. Unlike theheader in other blocks 778 ₂ to 778 _(N) in the blockchain, the header772 ₁ in the genesis block does not reference a previous block, simplybecause there is no previous block.

The original file 774 ₁ in the genesis block may be, for example, dataas captured by a device with or without processing prior to itsinclusion in the blockchain. The original file 774 ₁ is received throughthe interface of the system from the device, media source, or node. Theoriginal file 774 ₁ is associated with metadata, which, for example, maybe generated by a user, the device, and/or the system processor, eithermanually or automatically. The metadata may be included in the firstblock 778 ₁ in association with the original file 774 ₁.

The value 776 ₁ in the genesis block is an initial value generated basedon one or more unique attributes of the original file 774 ₁. In oneembodiment, the one or more unique attributes may include the hash valuefor the original file 774 ₁, metadata for the original file 774 ₁, andother information associated with the file. In one implementation, theinitial value 776 ₁ may be based on the following unique attributes:

-   -   1) SHA-2 computed hash value for the original file    -   2) originating device ID    -   3) starting timestamp for the original file    -   4) initial storage location of the original file    -   5) blockchain network member ID for software to currently        control the original file and associated metadata

The other blocks 778 ₂ to 778 _(N) in the blockchain also have headers,files, and values. However, unlike the first block 772 ₁, each of theheaders 772 ₂ to 772 _(N) in the other blocks includes the hash value ofan immediately preceding block. The hash value of the immediatelypreceding block may be just the hash of the header of the previous blockor may be the hash value of the entire previous block. By including thehash value of a preceding block in each of the remaining blocks, a tracecan be performed from the Nth block back to the genesis block (and theassociated original file) on a block-by-block basis, as indicated byarrows 780, to establish an auditable and immutable chain-of-custody.

Each of the header 772 ₂ to 772 _(N) in the other blocks may alsoinclude other information, e.g., version number, timestamp, nonce, rootinformation, difficulty level, consensus protocol, and/or otherparameters or information associated with the corresponding files and/orthe blockchain in general.

The files 774 ₂ to 774 _(N) in the other blocks may be equal to theoriginal file or may be a modified version of the original file in thegenesis block depending, for example, on the type of processingperformed. The type of processing performed may vary from block toblock. The processing may involve, for example, any modification of afile in a preceding block, such as redacting information or otherwisechanging the content of, taking information away from, or adding orappending information to the files.

Additionally, or alternatively, the processing may involve merelycopying the file from a preceding block, changing a storage location ofthe file, analyzing the file from one or more preceding blocks, movingthe file from one storage or memory location to another, or performingaction relative to the file of the blockchain and/or its associatedmetadata. Processing which involves analyzing a file may include, forexample, appending, including, or otherwise associating variousanalytics, statistics, or other information associated with the file.

The values in each of the other blocks 7762 to 776N in the other blocksare unique values and are all different as a result of the processingperformed. For example, the value in any one block corresponds to anupdated version of the value in the previous block. The update isreflected in the hash of the block to which the value is assigned. Thevalues of the blocks therefore provide an indication of what processingwas performed in the blocks and also permit a tracing through theblockchain back to the original file. This tracking confirms thechain-of-custody of the file throughout the entire blockchain.

For example, consider the case where portions of the file in a previousblock are redacted, blocked out, or pixelated in order to protect theidentity of a person shown in the file. In this case, the blockincluding the redacted file will include metadata associated with theredacted file, e.g., how the redaction was performed, who performed theredaction, timestamps where the redaction(s) occurred, etc. The metadatamay be hashed to form the value. Because the metadata for the block isdifferent from the information that was hashed to form the value in theprevious block, the values are different from one another and may berecovered when decrypted.

In one embodiment, the value of a previous block may be updated (e.g., anew hash value computed) to form the value of a current block when anyone or more of the following occurs. The new hash value may be computedby hashing all or a portion of the information noted below, in thisexample embodiment.

-   -   a) new SHA-2 computed hash value if the file has been processed        in any way (e.g., if the file was redacted, copied, altered,        accessed, or some other action was taken)    -   b) new storage location for the file    -   c) new metadata identified associated with the file    -   d) transfer of access or control of the file from one blockchain        participant to another blockchain participant

FIG. 7D illustrates an embodiment of a Block_(i) which may represent thestructure of the blocks in the blockchain 790 in accordance with oneembodiment. The Block_(i) includes a header 772 _(i), a file 774 _(i),and a value 776 _(i).

The header 772 _(i) includes a hash value of a previous blockBlock_(i-1) and additional reference information, which, for example,may be any of the types of information (e.g., header informationincluding references, characteristics, parameters, etc.) discussedherein. All blocks reference the hash of a previous block except, ofcourse, the genesis block. The hash value of the previous block may bejust a hash of the header in the previous block or a hash of all or aportion of the information in the previous block, including the file andmetadata.

The file 774 _(i) includes a plurality of data, such as Data 1, Data 2,. . . , Data N in sequence. The data are tagged with metadata Metadata1, Metadata 2, . . . , Metadata N which describe the content and/orcharacteristics associated with the data. For example, the metadata foreach data may include information to indicate a timestamp for the data,process the data, keywords indicating the persons or other contentdepicted in the data, and/or other features that may be helpful toestablish the validity and content of the file as a whole, andparticularly its use a digital evidence, for example, as described inconnection with an embodiment discussed below. In addition to themetadata, each data may be tagged with reference REF₁, REF₂, . . . ,REF_(N) to a previous data to prevent tampering, gaps in the file, andsequential reference through the file.

Once the metadata is assigned to the data (e.g., through a smartcontract), the metadata cannot be altered without the hash changing,which can easily be identified for invalidation. The metadata, thus,creates a data log of information that may be accessed for use byparticipants in the blockchain.

The value 776 _(i) is a hash value or other value computed based on anyof the types of information previously discussed. For example, for anygiven block Block_(i), the value for that block may be updated toreflect the processing that was performed for that block, e.g., new hashvalue, new storage location, new metadata for the associated file,transfer of control or access, identifier, or other action orinformation to be added. Although the value in each block is shown to beseparate from the metadata for the data of the file and header, thevalue may be based, in part or whole, on this metadata in anotherembodiment.

Once the blockchain 770 is formed, at any point in time, the immutablechain-of-custody for the file may be obtained by querying the blockchainfor the transaction history of the values across the blocks. This query,or tracking procedure, may begin with decrypting the value of the blockthat is most currently included (e.g., the last (N^(th)) block), andthen continuing to decrypt the value of the other blocks until thegenesis block is reached and the original file is recovered. Thedecryption may involve decrypting the headers and files and associatedmetadata at each block, as well.

Decryption is performed based on the type of encryption that took placein each block. This may involve the use of private keys, public keys, ora public key-private key pair. For example, when asymmetric encryptionis used, blockchain participants or a processor in the network maygenerate a public key and private key pair using a predeterminedalgorithm. The public key and private key are associated with each otherthrough some mathematical relationship. The public key may bedistributed publicly to serve as an address to receive messages fromother users, e.g., an IP address or home address. The private key iskept secret and used to digitally sign messages sent to other blockchainparticipants. The signature is included in the message so that therecipient can verify using the public key of the sender. This way, therecipient can be sure that only the sender could have sent this message.

Generating a key pair may be analogous to creating an account on theblockchain, but without having to actually register anywhere. Also,every transaction that is executed on the blockchain is digitally signedby the sender using their private key. This signature ensures that onlythe owner of the account can track and process (if within the scope ofpermission determined by a smart contract) the file of the blockchain.

FIG. 8 is not intended to suggest any limitation as to the scope of useor functionality of embodiments of the application described herein.Regardless, the computing node 800 is capable of being implementedand/or performing any of the functionality set forth hereinabove.

In computing node 800 there is a computer system/server 802, which isoperational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing systems, environments, and/or configurations that may besuitable for use with computer system/server 802 include, but are notlimited to, personal computer systems, server computer systems, thinclients, thick clients, hand-held or laptop devices, multiprocessorsystems, microprocessor-based systems, set top boxes, programmableconsumer electronics, network PCs, minicomputer systems, mainframecomputer systems, and distributed cloud computing environments thatinclude any of the above systems or devices, and the like.

Computer system/server 802 may be described in the general context ofcomputer system-executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 802 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in FIG. 8, computer system/server 802 in cloud computing node800 is shown in the form of a general-purpose computing device. Thecomponents of computer system/server 802 may include, but are notlimited to, one or more processors or processing units 804, a systemmemory 806, and a bus that couples various system components includingsystem memory 806 to processor 804.

The bus represents one or more of any of several types of busstructures, including a memory bus or memory controller, a peripheralbus, an accelerated graphics port, and a processor or local bus usingany of a variety of bus architectures. By way of example, and notlimitation, such architectures include Industry Standard Architecture(ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA)bus, Video Electronics Standards Association (VESA) local bus, andPeripheral Component Interconnects (PCI) bus.

Computer system/server 802 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 802, and it includes both volatileand non-volatile media, removable and non-removable media. System memory806, in one embodiment, implements the flow diagrams of the otherfigures. The system memory 806 can include computer system readablemedia in the form of volatile memory, such as random-access memory (RAM)810 and/or cache memory 812. Computer system/server 802 may furtherinclude other removable/non-removable, volatile/non-volatile computersystem storage media. By way of example only, storage system 814 can beprovided for reading from and writing to a non-removable, non-volatilemagnetic media (not shown and typically called a “hard drive”). Althoughnot shown, a magnetic disk drive for reading from and writing to aremovable, non-volatile magnetic disk (e.g., a “floppy disk”), and anoptical disk drive for reading from or writing to a removable,non-volatile optical disk such as a CD-ROM, DVD-ROM or other opticalmedia can be provided. In such instances, each can be connected to thebus by one or more data media interfaces. As will be further depictedand described below, memory 806 may include at least one program producthaving a set (e.g., at least one) of program modules that are configuredto carry out the functions of various embodiments of the application.

Program/utility 816, having a set (at least one) of program modules 818,may be stored in memory 806 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 818 generally carry out the functionsand/or methodologies of various embodiments of the application asdescribed herein.

As will be appreciated by one skilled in the art, aspects of the presentapplication may be embodied as a system, method, or computer programproduct. Accordingly, aspects of the present application may take theform of an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “circuit,” “module” or “system.”Furthermore, aspects of the present application may take the form of acomputer program product embodied in one or more computer readablemedium(s) having computer readable program code embodied thereon.

Computer system/server 802 may also communicate with one or moreexternal devices 820 such as a keyboard, a pointing device, a display822, etc.; one or more devices that enable a user to interact withcomputer system/server 802; and/or any devices (e.g., network card,modem, etc.) that enable computer system/server 802 to communicate withone or more other computing devices. Such communication can occur viaI/O interfaces 824. Still yet, computer system/server 802 cancommunicate with one or more networks such as a local area network(LAN), a general wide area network (WAN), and/or a public network (e.g.,the Internet) via network adapter 826. As depicted, network adapter 826communicates with the other components of computer system/server 802 viaa bus. It should be understood that although not shown, other hardwareand/or software components could be used in conjunction with computersystem/server 802. Examples, include, but are not limited to: microcode,device drivers, redundant processing units, external disk drive arrays,RAID systems, tape drives, and data archival storage systems, etc.

Although an exemplary embodiment of at least one of a system, method,and non-transitory computer readable medium has been illustrated in theaccompanied drawings and described in the foregoing detaileddescription, it will be understood that the application is not limitedto the embodiments disclosed, but is capable of numerous rearrangements,modifications, and substitutions as set forth and defined by thefollowing claims. For example, the capabilities of the system of thevarious figures can be performed by one or more of the modules orcomponents described herein or in a distributed architecture and mayinclude a transmitter, receiver or pair of both. For example, all orpart of the functionality performed by the individual modules, may beperformed by one or more of these modules. Further, the functionalitydescribed herein may be performed at various times and in relation tovarious events, internal or external to the modules or components. Also,the information sent between various modules can be sent between themodules via at least one of: a data network, the Internet, a voicenetwork, an Internet Protocol network, a wireless device, a wired deviceand/or via plurality of protocols. Also, the messages sent or receivedby any of the modules may be sent or received directly and/or via one ormore of the other modules.

One skilled in the art will appreciate that a “system” could be embodiedas a personal computer, a server, a console, a personal digitalassistant (PDA), a cell phone, a tablet computing device, a smartphoneor any other suitable computing device, or combination of devices.Presenting the above-described functions as being performed by a“system” is not intended to limit the scope of the present applicationin any way but is intended to provide one example of many embodiments.Indeed, methods, systems and apparatuses disclosed herein may beimplemented in localized and distributed forms consistent with computingtechnology.

It should be noted that some of the system features described in thisspecification have been presented as modules, in order to moreparticularly emphasize their implementation independence. For example, amodule may be implemented as a hardware circuit comprising custom verylarge-scale integration (VLSI) circuits or gate arrays, off-the-shelfsemiconductors such as logic chips, transistors, or other discretecomponents. A module may also be implemented in programmable hardwaredevices such as field programmable gate arrays, programmable arraylogic, programmable logic devices, graphics processing units, or thelike.

A module may also be at least partially implemented in software forexecution by various types of processors. An identified unit ofexecutable code may, for instance, comprise one or more physical orlogical blocks of computer instructions that may, for instance, beorganized as an object, procedure, or function. Nevertheless, theexecutables of an identified module need not be physically locatedtogether but may comprise disparate instructions stored in differentlocations which, when joined logically together, comprise the module andachieve the stated purpose for the module. Further, modules may bestored on a computer-readable medium, which may be, for instance, a harddisk drive, flash device, random access memory (RAM), tape, or any othersuch medium used to store data.

Indeed, a module of executable code could be a single instruction, ormany instructions, and may even be distributed over several differentcode segments, among different programs, and across several memorydevices. Similarly, operational data may be identified and illustratedherein within modules and may be embodied in any suitable form andorganized within any suitable type of data structure. The operationaldata may be collected as a single data set or may be distributed overdifferent locations including over different storage devices, and mayexist, at least partially, merely as electronic signals on a system ornetwork.

It will be readily understood that the components of the application, asgenerally described and illustrated in the figures herein, may bearranged and designed in a wide variety of different configurations.Thus, the detailed description of the embodiments is not intended tolimit the scope of the application as claimed but is merelyrepresentative of selected embodiments of the application.

One having ordinary skill in the art will readily understand that theabove may be practiced with steps in a different order, and/or withhardware elements in configurations that are different than those whichare disclosed. Therefore, although the application has been describedbased upon these preferred embodiments, it would be apparent to those ofskill in the art that certain modifications, variations, and alternativeconstructions would be apparent.

While preferred embodiments of the present application have beendescribed, it is to be understood that the embodiments described areillustrative only and the scope of the application is to be definedsolely by the appended claims when considered with a full range ofequivalents and modifications (e.g., protocols, hardware devices,software platforms etc.) thereto.

What is claimed is:
 1. A system, comprising: two or more ofauthorization entities; a blockchain system; wherein the blockchainsystem is configured to: receive two or more authorization decisionsfrom the two or more authorization entities; record the two or moreauthorization decisions into one or more blocks of a blockchain of theblockchain system; determine, by the blockchain system, whether the twoor more authorization decisions satisfy a policy to authorize access toat least one of a device or identifiable content on the device; andauthorize access to a public key that can be used to gain access to thedevice when the two or more authorization decisions satisfy the policy.2. The system of claim 1 comprising receive an access request for adevice into the blockchain system and distribute the access request tothe two or more authorization entities.
 3. The method of claim 2comprising store the access request in the blockchain.
 4. The system ofclaim 1 wherein the blockchain system is configured to receive thepublic key into the blockchain system and store the public key in ablock of the blockchain.
 5. The system of claim 1 wherein the policyrequirement requires at least two of the authorization entities toauthorize release of the public key.
 6. The system of claim 1 whereinthe policy is implemented in chaincode of the blockchain system.
 7. Thesystem of claim 1 wherein the blockchain system is configured to receivesecure content from the device retrieved using the public key and storethe secure content in the blockchain.
 8. A method comprising: receivingtwo or more authorization decisions from two or more authorizationentities into a blockchain system; recording the two or moreauthorization decisions into one or more blocks of a blockchain of theblockchain system; determining, by the blockchain system, whether thetwo or more authorization decisions satisfy a policy to authorize accessto at least one of a device or identifiable content on the device; andwhen the two or more authorization decisions satisfy the policy,authorizing access to a public key that can be used to gain access tothe device.
 9. The method of claim 8 comprising receiving an accessrequest pertaining to a device into the blockchain system anddistributing the access request to the two or more authorizationentities.
 10. The method of claim 9 comprising storing the accessrequest in the blockchain.
 11. The method of claim 8 comprisingreceiving the public key into the blockchain system and storing thepublic key in a block of the blockchain.
 12. The method of claim 8wherein the policy requirement requires at least two of theauthorization entities to authorize release of the public key.
 13. Themethod of claim 8 wherein the policy is implemented in chaincode of theblockchain system.
 14. The method of claim 8 comprising retrievingsecure content from the device using the public key and storing thesecure content in the blockchain.
 15. A non-transitory computer readablemedium comprising instructions, that when read by a processor, cause theprocessor to perform: receiving two or more authorization decisions fromtwo or more authorization entities into a blockchain system; recordingthe two or more authorization decisions into one or more blocks of ablockchain of the blockchain system; determining, by the blockchainsystem, whether the two or more authorization decisions satisfy a policyto authorize access to at least one of a device or identifiable contenton the device; and when the two or more authorization decisions satisfythe policy, authorizing access to a public key that can be used to gainaccess to the device.
 16. The non-transitory computer readable medium ofclaim 15 comprising instructions that cause the processor to performreceiving an access request pertaining to a device into the blockchainsystem and distributing the access request to the two or moreauthorization entities.
 17. The non-transitory computer readable mediumof claim 16 comprising instructions that cause the processor to performstoring the access request in the blockchain.
 18. The non-transitorycomputer readable medium of claim 15 comprising instructions that causethe processor to perform receiving the public key into the blockchainsystem and storing the public key in a block of the blockchain.
 19. Thenon-transitory computer readable medium of claim 15 wherein the policyrequirement requires at least two of the authorization entities toauthorize release of the public key.
 20. The non-transitory computerreadable medium of claim 15 wherein the policy is implemented inchaincode of the blockchain system.